Phoenix (CNN) -- Mike Rioux can't go to the grocery store without making a list, even for a single item.

He can't drive without gripping the steering wheel so hard his knuckles turn white. And he can't stand any longer than 30 minutes because of severe back pain.

This is Rioux's life after Afghanistan, where firefights and a roadside bomb blast left him with a traumatic brain injury and post-traumatic stress disorder.

His ears still ring from the explosions. He suffers from vertigo, headaches, insomnia and nightmares. He has terrible anxiety, evident in an interview with CNN -- Rioux could hardly sit still, and his memory loss and inability to concentrate meant questions had to be repeated at times.